Plate-glass-inspection apparatus



March 31, 1931. e. E. P. WRIGHT PLATE GLASS INSPECTION APPARATUS Filed May 21, 1929 3 Sheets-Sheet l gan March 31, 1931. G E P, w l T 1,798,573

PLATE GLASS INSPECTION APPARATUS Filed May 21, 1929 3 Sheets-Sheet 2 1) a)! INVENTOR PLATE GLASS INSPECTION APPARATUS Filed May 21, 1929 3 Sheets-Sheet 3 g @0 i J; a. J 4 4 wfifi 1 E g M J b I 1 a 1 3 F 5 Q a v 2 9 2 a Patented Mar. 31, 1931 UNITED STATES PATENT OFFICE GORDON E. P. WRIGHT, OF FORD CITY, PENNSYLVANIA, ASSIGNOR TO PITTSBURGH PLATE GLASS COMPANY, A CORPORATION OF PENNSYLVANIA PLATE-GLASS-INSIPECTION APPARATUS Application filed May 21,

The invention relates to plate glass inspection apparatus. It has for its objects; the provision of an improved apparatus'permitting the rapid and thorough inspection of the glass; the provision of'an apparatus in whose use the loss of time by the inspector between plates is reduced to a minimum; and the provision of an apparatus in whose use every part of the plate inspected'is exposed without obstruction to the vision of the inspector and under uniform conditions of illumination. One embodiment of the invention is illustrated in the accompanying drawings, wherein:

Figure 1 is a vertical section on the line II of Fig. 2. And Figs. 2, 3 and 4 are sections on the lines 11-11, III-III and IV-IV respectively of Fig. 1.

The construction preferably employs two light booths 1 and 2 of similar construction with an inspection platform 3 therebetween, so that while the operator on the platform is inspecting one sheet, another one is being positioned at the front of the other booth. The booths are preferably sheathed with corrugated metal 4 and are each provided with a set of lights 5, for inspection purposes, these preferably comprising electric light tubes with suitable reflectors. Since the booths, and

various devices connected therewith, are the same on both sides of the platform, a description of one will be sufficient for both.

The booth is preferably supported on four vertical channels '6, 6, 6, 6 anchored to the floor with suitable cross beams 7 and 8. Two

of the channels 6, 6 act as a support for the inspection frame at the front of the booth. The inspection frame comprises the vertical end bars 9, 9 secured to the channels 6, 6 and four cross bars 10, 10 and 11, 11 (Fig. 2). Se-

cured to these cross bars are the two sets of roller bars 12, 12 and 13, 13, the lower ends of the bars 12 being spaced away from the upper ends of the bars 13 to provide an inspection opening A (Fig. 1). The bars are each provided with a set of rollers 14*. The roller frame as thus constructed is preferably inclined to the rear slightly from its lower to its upper end, as indicated in Fig. 1, the purpose being to prevent the sheet of glass 1929. Serial No. 364,930.

under inspection from falling away from the frame accidentally after it has once been positioned.

In order to support the glass'sheet to be inspected, a lifting bar 14 is provided adjacent the base of the roller frame, such bar extending from one side of the booth to the other and being supported at its ends by a pair of cables 15 passing up around pulleys 16 and then down to a pair of drums 17. These drums are mounted on a shaft 18 driven from the motor 19 through the intermediary of suitable reduction gearing in the casing 20. The lifting bar is guided at its ends upon the vertical guide members 21, 21 (Fig. 4) secured to the channels 6, 6. .The bar has at each end a pair of angles 22 boltedthereto, as indicated in Fig. 4, with their flanges spaced apart to receive the flange of the guide member 21. The bar is cut away at 23 opposite each of the roller bars, as indicated in Fig. 4, so that during the upward movement of the bar, the glass rests against the rollers and the bar can pass the rollers without any interference therewith.

In operation, a sheet of glass is carried by the vacuum frame 24 to a position between the roller frames, as indicated in Fig. 1 and lowered so that its edge rests upon the lifting bar 14, such lifting bar being at this time positioned at the level of the inspection platform or at a point above such level, the vacuum frame now being released and carried away by means of an overhead crane to which the frame is attached by the cable 25, the lifting bar is lowered so that the upper edge of the glass plate comes opposite the inspection opening 14 at about the level of the vision of the inspector on the platform. The lifting bar' is now raised slowly by the'motor 17 so that theglass sheet moves past theline of vision-of the inspector. This continues until the entire sheet has been inspected, the inspector marking the glass for defects in the usual way as'the sheet moves upward. During this inspection, another sheet is brought from the racks by the vacuum frame 24 and placed on the other lifting bar so that, by the time the inspector has finished with one sheet,

the next sheet is ready for inspection and no time is lost incident to transfer of the sheets from the storage racks to the inspection apparatus. After a sheet has been inspected, it is engaged by the vacuum frame and carried away. In this manner the sheets may be inspected rapidly and with a minimum effort on the part of the inspector who has merely to walk back and forth on the platform as the glass moves upward slowly past his line of vision. The advantages-of this method of inspection and the apparatus for carryingout the method will be readily apparent tothose skilled in the art.

What I claim is 1. In combination in an inspection apparatus for plate glass, an upright roller frame inclined slightly to the vertical, upright guide-ways along the side edges of the frame, a lifting bar mounted for vertical movement on said guide-ways and adapted to support the lower edge of the glass sheet to be inspected and means for moving the bar upwards to carry the sheet across the line of vision of an inspector. v

2. In combination in, an inspection apparatus for plate glass, an upright frame inclined slightly to the vertical and provided with vertical rows of rollers for supporting the glass sheet to be inspected, upright guideways along the side edges of the frame, a lifting bar mounted for movement upward on the guide-ways and adapted to support the lower edge of the glasssheet, andmeans for moving the bar upwards to carry the sheet across the line of vision of an inspector, said lifting bar being recessed on its rear'side at intervals to avoid interference with said rollers. V

3. In combination in an inspection apparatus for plate glass, an upright roller frame inclined slightly to the vertical, upright guide-ways along the side edges of the frame, a liftingbar mounted for vertical movement on said guide-ways and adapted to support the lower edge of the glass sheet to. be in;- spected, a booth partially surrounding the guide frame, lighting means in the booth'back of the guide frame, and means for moving the bar upwards to-carry the sheet pastsaid light ing means and the line of vision of an inspector.

4. In combination in an inspection apparatusfor plate glass, a pair of upright roller frames spaced apart in opposition, a lifting bar for each frame adapted to. support the lower edges of the sheets to be inspected,"and means for moving the bars upward to carry the sheets past the line of vision of an inspecs tor.

5. In combination in an inspection appas ratus for plate-glass a pair of upright roller frames spacedapart in opposition, a lifting bar foreach frame adapted to supportthe lower edges of thesheets to be inspected, a casing behind each frame, lighting meansvin each casing, and means for moving the lifting bars upward to carry the sheets past said lighting means and the line of vision of an inspector.

6. In combination in an inspection apparatus for plate glass, an upright roller frame consisting of a pair of end uprights, a plurality of upright bars intermediate said end uprights each provided on its front side with a series of rollers, and cross bars between the end uprights supporting the upright intermediate bars, upright guide-ways along the side edges of the frame, a lifting barhmounted for movement upward on the guide-ways and adapted to support the lower edge of the glass plate to be=inspected, and means for moving'the bar upward to carry the plate past the-line of vision of an inspector, said upright bars all being interrupted intermediate their ends at a common level-to provide a clear space for inspection purposes.

In testimony whereof, I have hereunto-sub.-

scribed my name this 2&th day of April, 1929.

GORDON E. P. WRIGHT. 

